Electron discharge apparatus



March 31,1936; ETAL 2,035,784-

ELECTRON DISCHARGE APPARATUS Filed July 5, 1935 g lnvent'ors': I I Cornelis Bo'l,

' Willem'De Groofq I Mari Johan Di uyyestegh,

- 2f. by T emttovneg.

Patented Mar. 31, 1936 UNITED STATES- ELECTRON DISCHARGE APPARATUS Cornelis Bol, Willem de Groot, and Mari J. Druyvesteyn, Eindhoven, Netherlands, assignors to General Electric New Yorlr Company, a corporation of Application Jilly 3, 1933, Serial No. 678,974

, In the Netherlands June 30, 1932 Claims. (01. 176122) The present invention relates to electron discharge apparatus, more particularly to glow discharge tubes used for illumination purposes.

' In the operation oftwo or more gas discharge 5 7 paths having negative current-voltage characteristics, it has been considered necessary to employ impedances in the circuits connected to the discharge paths in order that the latter may be operated in parallel.

Applicants have discovered, and in accordance with the present invention, that two or more discharge paths may be successfully operated in parallel without theimpedance connection, provided the paths'are contained in a single envelope and have a common glow cathode. In this case, the anodes are conveniently connected together. Ap-

plicants have also found that theparallel opera tion is possible'under these improved conditions, even if the discharge paths, formed between the anodes and the glow cathode, are separated over their entire lengths; i. e., even if they do not coincide or overlap for any appreciable part of their lengths. This affords the possibility of utilizing a single glow cathode for two or more discharge paths and of mounting the anodes on opposite sides of the glow cathode. Thus, if the tube contains two anodes, these may be placed at equal or approximately equal distances on op- 'posite sides of the glow cathode. This arrangement .of the electrodes causes the electric dis-v an improved lighting apparatus utilizing a plurality of glow discharge paths of the negative volt-ampere characteristic type, in parallel, without the necessity of providing current stabilizing or equalizing impedances.

tion and broken away, of a glow discharge lamp improved in accordance with the present invention. In the drawing, numeral l designates 9. cylindrical envelope which is provided with a circular nick or groove Zinterm'ediate of its length and which terminates at the bottom in a reentrant stem 3 and a press 4. Within the envelope,

1 there is a filamentary cathode 5 positioned preferably approximately mid-way between the upper end of the envelope and the groove 2. This cathode may be constituted of a tungsten helix and is supported from the press 4 by means of rigid leading-in conductors 6 which are surrounded over a portion of their lengths by sleeves I of insulating material, such as glass or alumina.

paths have a negative or slightly The drawing shows a view, partly in cross sec-- ances.

takes place over the entire length of the tube.

The helix is mounted in a position preferably at right angles to the longitudinal axis of the tube, as shown, and may be coated, if desired, with electron-emitting material.

On opposite sides of the cathode 5, preferably 5 at equal distances therefrom, there are we pair of anodes 8 which may take the form of a flat metal plate. The anodes are so mounted as to be in transverse planes, parallel to the plane of the filament 5. The anodes are supported from 1 the press by means of rigid leading-in conductors 9 which are surrounded over substantially their entire lengths by tubes In of insulating material which rest at their lower ends on the upper surface of the pressd.

The various leading-in conductors are taken through the press 4 to the exterior by means of wires of suitable material which permit of hermetic sealing. The two anode conductors are connected together, either outside the tube as 20 shown, or within the envelope.

The discharge tube contains a quantity of rare gas such as neon at a pressure of about one millimeter or, if desired, a light-producing vapor such as sodium may also be used to advantage, 25 I in which case a quantity of metallic sodium is placed in the upper part of the tube. This part of the envelope is separated and closed off from the lower part by a partition ll of insulating material which serves to prevent condensation of. 30 the sodium vapor about the stem in the lower part of the tube.

During operation, a glow discharge is produced between the cathode 5 and each of the anodes 8 and, notwithstanding the fact that the discharge 35 negative voltampere characteristic, it is found that the discharge flows to both of the anodes even without 't use of external current-equalizing imped- As a result, the light emitting discharge 40 The ignition or starting voltage, also the operating voltage, are determined by the distance between the cathode and the anode which may be positioned closer to the cathode. In the case of 5 the tube as illustrated, in which the anodes are positioned at equal distances from the cathode, the ignition and operating voltages are determined by one-half of the spacing between the anodes even though the discharge takes place 50 over the entire length of the tube.

What we claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric dischargedevice comprising an envelope containing a filamentary cathode, a 55 material, said anodes being mounted at substantially equal distances on opposite sides of the cathode and being directly connected together electrically.

3. A glow lamp having an envelope of elonated configuration, said envelope containing a thermionically active cathode, a plurality of anodes and ionizable material, said anodes being mounted near the extremities of the tube, and

said cathode being positioned between said anodes, said anodes being electrically connected together. 4. A glow lamp comprising an envelope terminating in a reentrant stem, a partition extending across said envelope for separating the stem from the main portion of the envelope, a cathode, a pair of anodes and vaporizable, ionizable material in said main envelope portion, said electrodes being supported from said stem, said anodes being mounted on opposite sides of said cathode and being electrically connected together.

5. A glow lamp comprising an envelope terminating in a reentrant stem, a partition extending across said envelope for separating the stem from the main portion of the envelope, a cathode, a pair of anodes and vaporizable, ionizable material in said main envelope portion, said electrodes being supported from said stem and said anodes being mounted on opposite sides of said cathode at equal distances therefrom and being electrically connected together. i

CORNELIS BOL.

DE GROOT. MARI J. DRUYVES'I'EYN. 

